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[billy sharpstick]

Nu-Wave 220v. 5.5kw system, model MM-1. (It could be an MM-2. The panel cover was never marked.) Originally installed about ten years ago.

I'm not even sure of the nomenclature. Control panel? The box with the circuit board in it basically.

(I was an industrial electrician for several years, so consider myself reasonably competent with electrical systems)

My system popped the breaker recently. I discovered that the Cutler Hammer GFI breaker had failed. Replacement would have been $165, but I got a whole new disconnect box from Home Depot with GE 50a GFI for $65. Go figure. Fired it up and it instantly tripped. I disconnected the heater leads and all the external pieces and it still trips, but only on one of the hot leads(L1). Assuming that the new breaker is not defective, I deduced that there must be a short to ground somewhere inside the circuit board. My only other plan for troubleshooting is to unscrew the circuit board and look underneath for something shorting out.

I could call in a service guy to confirm, but would probably end up paying more in the long run.

Bottom line, I think I need a whole new box. I see most come with heaters built in. I suspect my old heater is still good.

We're hoping to keep the cost low because we are selling the house in the next year or two.

The most likely replacement I've seen so far is an "epack" from distributors-fulfillment, http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=121049416769

for $327. It's only 4kw, so I suspect it will take a bit longer to heat up. The old 300 gallon tub would go from 85 to 100 in about 90 minutes. He will include an LED light and extra large keypad for no extra cost.

Is this a good unit for the price? Are there any lower cost adequate alternatives? I've seen a couple a bit cheaper.

[Spa_Guru]

I have seen cases like this where a critter crawls into the spa pak and gets barbecued between the back of the board and the box.

Worth a look before you spend hundreds.

When you disconnected the heater, did you disconnect both leads?

The reason I ask is I have preformed over 40,000 service calls in 29 years and never had the board at fault for a GFI tripping.

[billy sharpstick]

Yes, I did. I even disconnected the ground wire coming in from the GFI. I'm sort of stumped. Disassembly is next.

Thanks

[Spa_Guru]

Here is another possibility, is the neutral wire from the spa hooked to the third breaker terminal, or is it connected with the other white wires?

Regardless of industrial experience, many electricians without spa experience hook all the white wires together, and that isn't how

240v GFI's work.

[Spa_Guru]

[Spa_Guru]

[billy sharpstick]

(Been out of town)

I'm pretty sure it is wired that way. The whole disconnect box was preassembled. I'll check today.

[Spa_Guru]

It is extremely common for experienced electricians to place all the white wires together and get exactly the results you have.

[iced98lx]

It is extremely common for experienced electricians to place all the white wires together and get exactly the results you have.

They did it on my first spa install, so I agree.